#include<bits/stdc++.h>
//#pragma GCC optimize("O2")
using namespace std;
using ll = long long;
using ld = long double;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define sz(x) (int)x.size()
#define endl '\n'
const int mod = 1e9 + 7;
const int inf = 2e9 + 5;
const ll linf = 9e18 + 5;
int n, m, q;
const int N = 1e5 + 5;
const int M = 2e5 + 5;
const int S = 300;
vector<int> adj[N];
pair<int, int> vert[N][S];
bool ok[N];
void init() {
fill(ok + 0, ok + N, true);
}
void input() {
cin >> n >> m >> q;
for (int i = 1; i <= m; i++) {
int u, v;
cin >> u >> v;
adj[v].pb(u);
}
}
void cre() {
for (int u = 1; u <= n; u++) {
int inds[sz(adj[u])];
fill(inds + 0, inds + sz(adj[u]), 0);
int ind = 0;
while (ind < S) {
int bestind = -1;
pair<int, int> best = mp(-1, 0);
for (int i = 0; i < sz(adj[u]); i++) {
while (inds[i] < S) {
if (ok[vert[adj[u][i]][inds[i]].se]) {
break;
}
inds[i]++;
}
if (inds[i] == S) {
continue;
}
if (best < vert[adj[u][i]][inds[i]]) {
bestind = i;
best = vert[adj[u][i]][inds[i]];
}
}
if (bestind == -1) {
break;
}
best.fi++;
vert[u][ind] = best;
ok[best.se] = false;
ind++;
}
if (ind < S) {
vert[u][ind] = mp(0, u);
ind++;
}
while (ind < S) {
vert[u][ind] = mp(-1, 0);
ind++;
}
for (int i = 0; i < S; i++) {
ok[vert[u][i].se] = true;
}
}
}
int naive(int k) {
int dp[k + 1];
for (int u = 1; u <= k; u++) {
if (ok[u]) {
dp[u] = 0;
}
else {
dp[u] = -inf;
}
for (auto v : adj[u]) {
dp[u] = max(dp[u], dp[v] + 1);
}
}
return max(dp[k], -1);
}
void solve() {
cre();
fill(ok + 0, ok + n + 1, true);
while (q--) {
int t, y;
cin >> t >> y;
int verts[y];
for (int i = 0; i < y; i++) {
cin >> verts[i];
}
for (int i = 0; i < y; i++) {
ok[verts[i]] = false;
}
if (y >= S) {
cout << naive(t) << endl;
}
else {
for (int i = 0; i < S; i++) {
if (ok[vert[t][i].se]) {
cout << vert[t][i].fi << endl;
break;
}
}
}
for (int i = 0; i < y; i++) {
ok[verts[i]] = true;
}
}
}
void output() {
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int number_of_testcases = 1;
//cin >> number_of_testcases;
while (number_of_testcases--) {
init();
input();
solve();
output();
}
return 0;
}
